The present invention is especially applicable to mining machines and the like of the type having a primary drive member to which is affixed one or more base members each adapted to receive a bit holder which in turn receives a bit or cutting tool. The drive member, which in turn is driven by appropriate mechanisms, may take a number of forms such as a chain, a rotating wheel, a rotating drum or a rotating arm. The bits or cutting tools, which may also be those found in other machinery such as road working and earth moving equipment, may also take various forms such as mining machine cutter bits, road ripping elements, digger teeth and the like. All of the bits, cutting tools and the like contemplated for use in the arrangements of the present invention are characterized by having a body portion or shank provided with a cutting tip at at least one end. All of the various mounting means contemplated for use with this invention are provided with sockets or shank receiving perforations adapted to receive the body portion or shank of the bit, cutting tool and the like. Means are provided to retain the shank of the bit, cutting tool and the like in its respective mounting means during the mining, road working or earth digging operation. Means are also provided to maintain the mounting means on its respective base member which in turn is either affixed to, or made an integral part of, the drive member earlier mentioned.
Prior art workers have used many means to secure cutting tool shanks in shank receiving perforations provided in various mounting means. Set screws and other mechanical latching or locking devices have been used. A number of other arrangements, including various resilient retaining means and the like, which enabled, for example, the provision of a "knock-in", "pry-out" engagement between the cutting tool shank and the shank receiving perforation of the mounting means, have also been developed. Such a resilient retaining means is taught in U.S. Pat. No. 3,114,537. U.S. Pat. No. 2,965,365 also discloses quite satisfactory arrangements for accomplishing this. Furthermore, means for retaining a rotatable bit within a lug of a mining machine in such manner that the bit may be readily replaced are shown in U.S. Pat. No. 3,397,012. In U.S. Pat. No. 3,622,206 still other means are shown for enabling quick and easy removal of a non-rotatable cutting tool from its mounting means.
Prior art workers also recognized the importance of providing arrangements by means of which the mounting means itself could be easily and readily removed from the respective base member on which it was mounted. A number of "pin-on", "wedge-on" and other arrangements were developed for accomplishing that result. The present invention has particular application to those arrangements generally classified as "wedge-on". Athough no search of the United States prior art has been made with respect to the particular means employed for securing a mounting means to its base member, there are known United States Patents which do disclose various means of a "wedge-on" type for quickly and easily removing and replacing worn mounting means. FIG. 13 of U.S. Pat. No. 3,342,531 shows such a means in connection with a particular type of cutting tool or bit. FIG. 14 of U.S. Pat. No. 3,834,764 shows another type of wedging means. Other wedge arrangements are also disclosed in U.S. Pat. No. 4,057,294. United States application Ser. No. 936,840 filed Aug. 25, 1978 in the name of the same inventor and entitled MEANS FOR REMOVABLY AFFIXING A CUTTER BIT MOUNTING LUG TO A BASE MEMBER ON THE DRIVEN ELEMENT OF A MINING MACHINE OR THE LIKE (now U.S. Pat. No. 4,275,929 issued June 30, 1981) discloses further wedge arrangements.
The instant invention resides in an improved relationship among the mounting means, cutting tool or bit, and base member which vastly cuts down wear on both the mounting means and base member so that it is seldom necessary to remove the mounting means from the base member for replacement due to wear between the mounting means and base member.